Continuous positive airway pressure (CPAP) therapy has been proven to be an effective treatment for some respiratory conditions, such as obstructive sleep apnea, and there are many types of CPAP devices commercially available for patients.
In order to relieve the discomfort to patients caused by dry respiratory tract during the CPAP therapy, some CPAP devices are equipped with a gas humidifier for humidifying gas to a proper humidity level before delivery to the patients. Typically, a gas humidifier is composed of a liquid container and humidification means, such as a heater or an ultrasonic atomizer. Although a higher capacity of the liquid container increases the amount of liquid accommodated therein for long-time use, such as up to eight hours, a higher initialization power will be required for humidifying more liquid, and it will take more time to achieve a predetermined gas humidity.
One humidifier chamber has been proposed, characterized by using a thermal insulating partition to divide the chamber into a heated reservoir and a supply reservoir, wherein a liquid channel is formed below the partition to allow liquid communication between the two reservoirs.
Also proposed is a pressure support system which has a humidifier containing a holding space, a humidification space and a partition separating the two spaces, an opening being defined on the partition to allow liquid communication between the two spaces.
However, there are still needs to improve conventional designs, particularly to address the problems associated with bi-directional liquid communication.